From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754942Ab2FMWWI (ORCPT ); Wed, 13 Jun 2012 18:22:08 -0400 Received: from mailout-de.gmx.net ([213.165.64.22]:43674 "HELO mailout-de.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1754890Ab2FMWWB (ORCPT ); Wed, 13 Jun 2012 18:22:01 -0400 X-Authenticated: #12255092 X-Provags-ID: V01U2FsdGVkX1+CaSwEByKCkRfqdG1YirpWuM4yHuqoo44AbRE/Pl phEOiOjBspft7R From: Peter Huewe To: Greg Kroah-Hartman Cc: Arnaud Patard , Aaro Koskinen , Dan Carpenter , Peter Huewe , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org Subject: [PATCH 02/14] staging/xgifb: Add mutext for fb_mmap locking Date: Thu, 14 Jun 2012 00:21:40 +0200 Message-Id: <1339626112-20671-2-git-send-email-peterhuewe@gmx.de> X-Mailer: git-send-email 1.7.3.4 In-Reply-To: <1339626112-20671-1-git-send-email-peterhuewe@gmx.de> References: <1339626112-20671-1-git-send-email-peterhuewe@gmx.de> X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds a mutex for fb_mmap around smem_start and smem_len so the mutex inside the fb_mmap() is actually used. Changing of these fields before calling the framebuffer_register() are not mutexed. We check whether framebuffer_register has been called by reading fbinfo->count. See 537a1bf0 - "fbdev: add mutex for fb_mmap locking" by Krzysztof Helt for details. Signed-off-by: Peter Huewe --- drivers/staging/xgifb/XGI_main_26.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/drivers/staging/xgifb/XGI_main_26.c b/drivers/staging/xgifb/XGI_main_26.c index ff88f1d..f427b85 100644 --- a/drivers/staging/xgifb/XGI_main_26.c +++ b/drivers/staging/xgifb/XGI_main_26.c @@ -1350,10 +1350,17 @@ static int XGIfb_get_fix(struct fb_fix_screeninfo *fix, int con, strncpy(fix->id, "XGI", sizeof(fix->id) - 1); - fix->smem_start = xgifb_info->video_base; + /* if register_framebuffer has been called, we must lock */ + if (atomic_read(&info->count)) + mutex_lock(&info->mm_lock); + fix->smem_start = xgifb_info->video_base; fix->smem_len = xgifb_info->video_size; + /* if register_framebuffer has been called, we can unlock */ + if (atomic_read(&info->count)) + mutex_unlock(&info->mm_lock); + fix->type = FB_TYPE_PACKED_PIXELS; fix->type_aux = 0; if (xgifb_info->video_bpp == 8) -- 1.7.3.4